A simple experiment that demonstrates the “green flash”

Courtial, J. (2012) A simple experiment that demonstrates the “green flash”. American Journal of Physics, 80(11), p. 955. (doi: 10.1119/1.4746384)

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The green flash occurs when, under certain atmospheric conditions, the top segment of the low sun is visibly green. It is surrounded—in at least a few minds—by an air of mystery. I describe a simple experiment that demonstrates different aspects of the green flash. The experiment uses an odd-shaped, water-filled, fish tank to simulate the refractive properties of the atmosphere; milk powder added to the water mimicks the atmosphere’s scattering properties. A circular white-light source is viewed through the fish tank and the combination of refraction and scattering makes one end of the light source look green. The setup also allows experimentation with mirage effects, thereby drawing attention to their often neglected contribution to the green flash.

Item Type:Articles
Glasgow Author(s) Enlighten ID:Courtial, Dr Johannes
Authors: Courtial, J.
College/School:College of Science and Engineering > School of Physics and Astronomy
Journal Name:American Journal of Physics

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